Maternal nutritional status during pregnancy is an important determinant of fetal growth. Although the effects of several nutrients and foods have been well examined, little is known about the relationship of overall maternal diet in pregnancy to fetal growth, particularly in non-Western populations. We prospectively examined the relationship of maternal dietary patterns in pregnancy to neonatal anthropometric measurements at birth and risk of small-for-gestational-age (SGA) birth among 803 Japanese women with live-born, singleton, term deliveries. Maternal diet in pregnancy was assessed using a validated, self-administered diet history questionnaire. Dietary patterns from thirty-three predefined food groups (g/4184 kJ) were extracted by cluster analysis. The following three dietary patterns were identified: the ‘meat and eggs’ (n 326), ‘wheat products’, with a relatively high intake of bread, confectioneries and soft drinks (n 303), and ‘rice, fish and vegetables’ (n 174) patterns. After adjustment for potential confounders, women in the ‘wheat products’ pattern had infants with the significantly lowest birth weight (P = 0·045) and head circumference (P = 0·036) among those in the three dietary patterns. Compared with women in the ‘rice, fish and vegetables’ pattern, women in the ‘wheat products’ pattern had higher odds of having a SGA infant for weight (multivariate OR 5·2, 95 % CI 1·1, 24·4), but this was not the case for birth length or head circumference. These results suggest that a diet high in bread, confectioneries, and soft drinks and low in fish and vegetables during pregnancy might be associated with a small birth weight and an increased risk of having a SGA infant.

Although several nutrients and foods are suggested to be preventive against postpartum depression, all previous studies have primarily focused on single nutrients or foods. In contrast, studies on dietary patterns, namely the measurement of overall diet by considering the cumulative effects of nutrient, may provide new insights into the influence of diet on postpartum depression. We prospectively examined the association between dietary patterns during pregnancy and the risk of postpartum depression among 865 Japanese women. Diet was assessed with a validated, self-administered diet history questionnaire. Dietary patterns from thirty-three predefined food groups (energy-adjusted food (g/d)) were extracted by factor analysis. Postpartum depression was defined as present when the subjects had an Edinburgh Postnatal Depression Scale score of ≥ 9 at 2–9 months postpartum. A total of 121 women (14·0 %) were classified as having postpartum depression. Three dietary patterns were identified: ‘Healthy’, ‘Western’ and ‘Japanese’ patterns. After adjustment for potential confounders, neither the ‘Healthy’ nor the ‘Japanese’ pattern was related to the risk of postpartum depression. Compared with the first quartile of the ‘Western’ pattern, only the second quartile was independently related to a decreased risk of postpartum depression (multivariate OR 0·52, 95 % CI 0·30, 0·93), although no evident exposure–response associations were observed (P for trend = 0·36). The present study failed to substantiate clear associations between dietary patterns and the risk of postpartum depression. Further studies with more accurate measurements are warranted to confirm the relationship between dietary patterns and the risk of postpartum depression.